In railway technology, level crossings are known, in which a railroad including a railway track crosses, at a same level on the ground, a road dedicated to ground vehicles such as cars and/or pedestrians. Such level crossings are often equipped with protection systems, comprising warning signals that can be selectively activated whenever a train is approaching. This way, vehicles and pedestrians coming from the road are prevented from crossing the railway track until the train has passed. Such protection systems are typically commanded by a central interlocking facility, which activates them whenever it detects an incoming train. It is highly desirable that such level crossing systems remain in a closed state for a duration as short as possible, e.g. that the level crossing protection time is as low as possible, in order not to disrupt traffic on the road.
One such method is known of US 2011/0133038 A1, in which, whenever an incoming train is detected approaching a level crossing, the interlocking facility waits for a certain amount of time before initiating the closure of the barriers of the protection system. This amount of time is calculated as a function of the incoming train's speed, as measured by trackside equipment. Taking account of the train's speed avoids closing the barriers too early, for example when the train is moving slowly and still far away from the level crossing.
A drawback of this known method is that measurement of the train's speed does not take into consideration that the train may slow down or accelerate during the measurement. It does not take either into consideration that the measurement takes time, not only due to the time required for averaging the measured speed, but also due to the propagation time of data between the train, the trackside equipment and the interlocking facility. This lack of precision has the consequence that the level crossing may remain closed for much longer than necessary, causing unwanted disruption to the traffic on the road.